The present invention relates generally to mailing machines having a postage meter which prints postage indicia on envelopees as they are fed sequentially along a feed path extending through the mailing machine, and more particularly to a tape feeding, cutting and ejecting apparatus for such mailing machines which enables the postage meter to print the postage indicia on the tape.
The present invention is an improvement on the tape feeding, cutting and ejecting apparatus disclosed and claimed in copending U.S. patent application Ser. No. 08/180,163, filed on Jan. 11, 1994, in the names of Morton Silverberg, William A. Salancy and Steven A. Supron, and assigned to the assignee of this application.
A detailed discussion of the advantages of incorporating the capability of printing postage indicia on tape, as well as the problems and difficulties encountered with the tape feeding, cutting and ejecting mechanisms of prior art mailing machines, is set forth in the five paragraphs following the first paragraph of the above mentioned copending application, which discussion is incorporated herein by reference. Further, certain advantageous features of the tape feeding, cutting and ejecting mechanism disclosed and claimed in the above mentioned copending application are discussed in the next paragraph following the five just mentioned, and that discussion is likewise incorporated herein by reference since those advantageous features are applicable to the corresponding improved apparatus disclosed and claimed in this application.
Although the tape feeding, cutting and ejecting mechanism disclosed and claimed in the above mentioned copending application worked in principle, it became apparent after building and operating that mechanism that it had a number of functional problems which would have a substantial adverse impact on the marketability of mailing machines incorporating that mechanism. One major problem resulted from utilizing the postage meter printing mechanism to pull the tape from the tape supply roll through the guide members of the first feed path as well as the feeding means, after the leading edge of the tape was gripped between the printing die and the impression roller of the printing mechanism. The problem was that it required a large force between the printing die and the impression roller to literally pull the tape through the necessary length of travel and the associated parts without the tape slipping in the printing mechanism and causing a smudged or blurred, and hence unacceptable, postage indicia. The ink used in postage meter printing devices is an effective lubricant, thereby facilitating slippage between the tape and the printing die if substantial drag is imposed on the tape in the absence of high pressing force between the printing die and the impression roller. In order to achieve the necessary pressing force to prevent the tape slippage and obtain tapes having acceptable print quality, it was necessary to utilize a heavy motor to drive the print drum of the postage meter on which the printing die is mounted, which increased the power consumption and operating noise of the postage meter compared to those utilizing prior art tape feeding, cutting and ejecting mechanisms.
Another major problem of the prior mechanism resulted from the design of the cutting device, which employed a stationary anvil or cutting blade against which a movable blade moved to cut the tape laterally in a manner similar to a scissors. Even though the anvil remained stationary during a cutting operation, it was, nevertheless, mounted for limited movement toward the movable blade and held against the movable blade by a heavy spring, in order to provide the contact pressure between the two blades necessary to cut the tape evenly and smoothly and also to compensate for wear on the blade surfaces, a slight amount of which could cause erratic cutting and jamming in the cutting mechanism. Thus, it required a large solenoid to activate the movable blade against the anvil, which required a heavy power consumption and made a considerable amount of objectionable noise. Also, the knife assembly did not have a long life due to the wear and tear on the knife blade from the high spring load.
Another problem of the prior apparatus was that provision had been made for driving the tape roll in a reverse or winding direction to rewind excess tape which had to be fed from the tape roll in order to bring a forward portion of the tape into the printing mechanism of the postage meter. Driving the tape roll in the reverse direction added some substantially complex structure which increased the cost of manufacture of the apparatus, the cost of operation in terms of higher power consumption and the possibility of malfunction and consequent need for service.